12 Answers

Your brain is absorbing the new information. The best thing you can do is plan regular breaks. That will actually help you learn faster and better. Plus you should only study for certain blocks of time a day. Anything more is counter productive.

For me I find it’s a momentum thing as well. When things are going well, I feel motivated to keep going. When I’m just not getting it, I want to stop. (That can be a sign of needing a break, I suppose…but if one keeps not getting it, it can be discouraging.)

@marinelife It’s hard when you have limited time to study, though. I work a full time job during the day and have class most evenings, so when I’m studying there’s not much time for a break…if I take a break, I’m out of time.

Attention relies on a process called working memory, which (we think) involves neurons actively firing to maintain a representation of the thing you’re trying to remember. Some theories suggest that when we try to learn something, it moves from working memory into short term memory and then into long term memory, and each of these has associated neural changes.

Why those neural changes can only support a limited attention span, though, is less clear. It could be a computational problem—that our neurons are only capable of maintaining x amount of representations, and once we hit that limit information needs to be moved into long term memory or it’ll get mixed up with the other representations. Or it could be a physiological limitation—the neurons run out of “juice” and can’t keep firing at the enhanced rate. Or it could be a motivational problem—maybe nothing has changed in your brain, but you’re bored and you just don’t want to study any more.

Great Question!—deeper than it seems at first. Metaphors such as “absorbing information” or “momentum” are useless at addressing neural mechanisms, but @nikipedia‘s GA is on the right track, I think.

I should think the need to take breaks from studying (I was a serious student for many years) is related to the need to take breaks from consciousness in general, i.e., sleep. I recall that there’s some evidence that consolidation of memory from short- to long-term benefits from intervening sleep.

To add to @nikipedia ‘s answer, there is also research to suggest that what’s actually fatiguing is the brain’s ability to suppress incoming distractions. The energy expended to keep attention directed at a specific target appears to go mostly toward the inhibitory mechanisms (involving the prefrontal cortex, the anterior cingulate cortex and the basal ganglia) that squelch competing stimuli. When this mechanism weakens, attention loses traction and gets pulled away in other directions.

How quickly the inhibitory mechanism gives out is dependent on overall arousal (as in how how awake one is) and strength of motivation.

I can’t speak for any of the scientific or psychological reasons. But I can tell you that the brain gets tired out just like any other part of your body. When I’m studying or doing schoolwork I have to take little breaks or I indeed get burnt out.

Every hour or so, I take 10 minutes (give or take) to rest my brain. I’ll go play a silly Flash game, or run downstairs to get a coffee, or take a shower, or come on Fluther and answer a couple of questions. It helps a ton, and has made getting through this year of grad school almost bearable :)

Remarking on the ‘why’ seems repetitious, given the responses. The breaks are incredibly important to productivity. I’m an avid reader/studier, and average a rough 12 hours daily…but this is only marked with success if it’s interspersed with breaks. I ascribe to the Pomodoro technique, simply because structure in breaks is far more beneficial than simply resting when you feel the need.

Just to add to @nikipedia‘s brilliant answer, studies have shown that students in heavy study for exams actually have a measurable increase in their grey matter volume. It takes energy to create these cells, to compute the networks they need to make, and to power them. New neural connections usually start out small, and grow as they are used more, so they require a greater amount of energy. You need to take a break so this tissue has time to form and develop.